Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (62,758)
Other Comprehensive Income (Loss), Transfers from Available-for-Sale Securities to Held-to-maturity, before Tax	0	$ (14,738)	$ 0
Personnel expense	482,676	428,976	424,676
Adjustment for adoption of ASU 2016-01	84
Interest income (amortization of net unrealized losses (gains) on available for sale securities transferred to held to maturity securities)	(572)	(2,665)	(5,887)
Total other comprehensive income (loss)	(62,214)	(8,079)	(22,063)
Ending Balance	(124,972)	(62,758)
Investments Securities Available For Sale
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(38,453)	(20,079)	459
Other comprehensive income (loss) before reclassifications	(39,891)	(27,040)	(17,900)
Investment securities losses (gains), net	1,985		(9,316)
Personnel expense	0	0	0
Other Expenses	0	0	0
Adjustment for adoption of ASU 2016-01	(84)
Adjustment for adoption of ASU 2018-02	(8,419)
Interest income (amortization of net unrealized losses (gains) on available for sale securities transferred to held to maturity securities)	(572)	(2,665)	(5,887)
Income tax (expense) benefit	9,791	11,331	12,565
Total other comprehensive income (loss)	(37,189)	(18,374)	(20,538)
Ending Balance	(75,643)	(38,453)	(20,079)
Defined Benefit Pension and Postretirement Obligations
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(24,305)	(34,600)	(33,075)
Other comprehensive income (loss) before reclassifications	(28,612)	14,273	(6,141)
Investment securities losses (gains), net	0		0
Personnel expense	(148)	(148)	(73)
Other Expenses	2,203	2,282	3,874
Adjustment for adoption of ASU 2016-01	0
Adjustment for adoption of ASU 2018-02	(5,235)
Interest income (amortization of net unrealized losses (gains) on available for sale securities transferred to held to maturity securities)	0	0	0
Income tax (expense) benefit	6,767	(6,112)	815
Total other comprehensive income (loss)	(25,025)	10,295	(1,525)
Ending Balance	(49,330)	(24,305)	(34,600)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(62,758)	(54,679)	(32,616)
Other comprehensive income (loss) before reclassifications	(68,503)	(12,767)	(24,041)
Investment securities losses (gains), net	1,985		(9,316)
Personnel expense	(148)	(148)	(73)
Other Expenses	2,203	2,282	3,874
Adjustment for adoption of ASU 2016-01	(84)
Adjustment for adoption of ASU 2018-02	(13,654)
Interest income (amortization of net unrealized losses (gains) on available for sale securities transferred to held to maturity securities)	(572)	(2,665)	(5,887)
Income tax (expense) benefit	16,558	5,219	13,380
Total other comprehensive income (loss)	(62,214)	(8,079)	(22,063)
Ending Balance	$ (124,972)	$ (62,758)	$ (54,679)

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Other Comprehensive Income (Loss), Transfers from Available-for-Sale Securities to Held-to-maturity, before Tax

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Reporting Comprehensive Income(2018-02)

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